The short answer for a hedgehog
A quick hedgehog health check happens in the evening, on his waking schedule: he should uncurl within a few minutes in a warm, dim room, walk steadily, and show clear eyes, a dry nose, and clean skin beneath the quills. You are looking for flaky or crusty skin, missing quills, sore feet, overgrown nails, lumps, and any change in how eagerly he explores or eats. Handle him over a soft surface with unhurried movements, because a startled hedgehog balls up tightly and then you can see nothing at all.
Let him uncurl and walk first
Place him on a fleece on the floor or table and give him time. A healthy hedgehog sniffs the air, lowers his quills, and sets off with a purposeful waddle; reluctance to uncurl, constant huffing long after he knows your scent, or a wobbly, dragging gait are all worth noting. Watch each leg move and look for limping or a foot that turns under. Feel his body temperature through the fleece: a hedgehog who feels cool to the touch and is sluggish in a properly warm room may be attempting to conserve energy in a dangerous way, and that combination needs prompt veterinary advice the same day.
Quills, skin, and ears up close
Once he is relaxed, look along the quill band and part the quills gently with your fingers to see the skin underneath. It should look clean and supple, not thickly flaky, crusty, or reddened, and quills should sit densely rather than in bald patches. Persistent scratching, heavy flaking, and quill loss together can accompany mites or skin infection, which only a vet can sort out properly. Check the ears for dry, tattered edges or crusting, and the eyes for brightness without swelling or discharge. A little self-anointing, where he licks a new smell into a foam and spreads it on his quills, looks strange but is normal behaviour, not a health sign.
Feet, nails, teeth, and weight
Hedgehog feet pick up threads and hair from bedding, which can wind tightly around a toe, so inspect all four feet closely and look for swelling or a strand digging in. Nails should be short enough not to curl; long nails catch on fleece and can tear. Glance at the mouth when he yawns or takes a treat for broken teeth, red gums, or a lump along the jaw, and feel gently along the body under the quills for any new swelling. Weigh him weekly at the same hour, because steady weight loss in an animal famous for loving food is an early clue that hides under the quills.
When the check becomes a vet call
Seek veterinary help promptly for a hedgehog who will not uncurl, feels cool and lethargic, breathes with noise or effort, stops eating, or develops wobbling that makes walking unsteady. Quill loss with crusty skin, a swollen foot, bleeding, watery droppings, or a lump that appears or grows also belong in front of a vet rather than in a home remedy. Write down when you first saw each change and what his appetite and weight have done since, because hedgehogs give few outward clues and that history carries real weight. Storing the timeline in KinsLe in the Pet Passport keeps it in one place, ready to share the moment an appointment is booked.